Many types of nitrogen fertilizers are available and vary by source, percentage of nutrient, and formulation. The fertilizer industry has standardized labeling to represent the “N” in the “N-P-K” label to represent the percent elemental N regardless of the form, while the P and K represent the percent of phosphate (P2O5) and potassium oxide (K2O), respectively.
It is critical to understand the form of nitrogen supplied in a fertilizer and distinguish which forms have the lowest risk of contaminating groundwater, while still providing a consistent release of nitrogen over time. Additionally, it is critical to understand the environment that the nitrogen fertilizer is being released into to ensure minimal off-site movement.
